Common problems with lights are lack of good grounds. Double check you grounding of the harness. There are specific gnd wires on the harness for head lights. Also make sure frame grounds etc are connected. Do you have Batt grounded to RH fender and engine block? Light switch needs to GRD to sheet metal.
The grounds on the headlight harness are grounded properly, the battery is grounded to the right fender and the block, the block is grounded to the frame and the firewall. The headlight switch is mounted to the dash and the high beam switch is screwed into the floor, is there another ground on the high beam floor switch besides being screwed into the floor??
